Crusher frame



J. C. MOTZ CRUSHER FRAME Sept. 29, 1964 3 Sheets-Sheef 1 Filed March 30,1962 Sept. 29, 1964 J. c. MOTZ 3,150,839

CRUSHER FRAME Filed March '30, 1962 3 Shee s-. heet 2 p 1964 J. c. MOTZ3,150,839

CRUSHER FRAME Filed March 50, .1962

3 Sheets-Sheer 3 1N VENTOR.

United States Patent 3,150,839 CRUSHER FRAME Jerome C. Mctz, Milwaukee,Wis, assignor to Nordberg Manufacturing Company, Milwaukee, Wis, acorporation of Wisconsin Filed Mar. 30, 1962, Ser. No. 183,795 16Claims. (Cl. 241---285) This invention relates to a cone crusher frame,and particularly relates to an assembled cone crusher frame.

An object of this invention is a cone crusher frame which may beeconomically assembled.

Another object is a cone crusher frame assembly which is adapted toreceive conventional complementary structures of a gyratory conecrusher.

Another object is a cone crusher frame in which component parts aredesigned for efiicient and economical assembly.

Another object is a cone crusher frame assembly characterized by reducedweight and bulk.

Another object is a cone crusher frame in which the number of castcomponents are reduced.

Another object is a cone crusher frame assembly wherein only the centerhub component is cast.

Another object is a cone crusher frame assembly wherein the center hubcomponent is cast and the remaining components are fabricated.

Another object is a cone crusher frame assembly wherein fabricatedcomponents are fixed about a centrally cast hub component by weld means.

Another object is a cone crusher frame assembly in which a fabricatedplate is adapted to receive the remaining components of the assembly.

Another object is a fabricated plate adapted to receive cast andfabricated components of a cone crusher frame assembly.

Another object is a fabricated plate with cut-out portions andspecialized areas adapted to securely engage components of a conecrusher frame assembly.

The foregoing objects as well as other objects which will becomeapparent from time to time are now realized by the invention which willbe described in detail and which is illustrated in the accompanyingdrawings wherein:

FIGURE 1 is a top plan view of an assembled cone crusher frame assembly,

FIGURE 2 is a sectional view along line 2-2 of FIG- URE 1,

FIGURE 3 is a top plan view of the fabricated plate,

FIGURE 4 is a side View partially in cross section of the center casthub component fixed to the fabricated plate,

FIGURE 5 is a view along line 55 of FIGURE 4,

FIGURE 6 is a section on an enlarged scale of the secured junction ofthe hub and fabricated plate,

FIGURE 7 is a view along line 7-7 of FIGURE 2,

FIGURE 8 is a fragmentary sectional view along line 8-8 of FIGURE 1,

FIGURE 9 is a view along line 99 of FIGURE 2,

FIGURE 10 is a fragmentary view on an enlarged scale along line 10-10 ofFIGURE 9,

FIGURE 11 is a section taken on an enlarged scale along line 11-11 ofFIGURE 1,

FIGURE 12 is a fragmentary view in section of the shell fixed to theupper ring, and

FIGURE 13 is a fragmentary sectional view along line 13-13 of FIGURE 1.

Like reference numerals will refer to the same structures in the variousviews of the drawings.

The cone crusher frame is assembled around a center hub 10 and a boss 11which are cast as one piece. The

ice

hub 10 has a central passageway in which an eccentric and shaft will beplaced to rotate a gyrating head in the completely assembled conecrusher. Keyway slots 9 are in the wall of the hub 10 so that theeccentric housing may be keyed therein. The shaft within the passagewayof the hub will be in an eccentric which eccentric will have a circulargear located at the top of the hub. The gear box that will enclose thisgear is formed by a curved wall 20 which is bent around the top of thehub and joined to the boss 11 on both sides of said boss. A portion ofplate 50 forms the floor of the gear box between the wall 20 and the hub10. The boss 11 has a passageway 12 through which the countershaft of apinion gear will pass. The pinion of said countershaft will engage thegear in the gear box. The front wall 113 of the boss 11 has a generallyeven surface parallel to the side 51 of the plate 50. In this front wall13 is found the generally annular passageway 12 to receive thecountershaft of the pinion. The side walls of the boss are contiguouswith the center hub and consist of inwardly angled segments 15 and 16flanking an intermediate straight segment 14 which is generally parallelto side 52. The bottom of the boss is shown generally tapered at thesides and the front as at 17, and has a flat floor 18 (FIGURES 2 and 5).The other side wall of boss 11 has similar straight segment 14a parallelto side 53 of plate 50, and inwardly angled segments 15:: and 16a.

Plate 50 is fabricated and adapted to receive other components of thecone crusher frame assembly. A top view of the fabricated plate is seenin FIGURE 3 wherein it is shown as a four-sided plate with opposed sides52, 53. The plate has a generally central bore 56 which is defined by anannular wedged end 55. The annular wedged end 55 is fixed to hub 10 atannular projection 10a by weld seal 101. Projection 10a and end wedge 55make contact at their respective high points as shown in FIGURE 6.Diverging spaces are formed on each side of the contact point and theweld mam 101 is placed in each diverging space. The weld 101 iswedgeshaped and is in the form of an annular fillet seam between plate56 and hub 10.

The bore 56 is interrupted by communicating cut out portion 57 whichextends from wedged end 55 to'side 51 of the plate. In plate 50 arespaced cut-out segments as at 58 which encircle said central bore 56 upto cut-out portion 57. Spaced between cut-out segments 55 are isthmusesor connecting bands 59 which connect inner annular band 60 with theouter portions of plate 50. Sides 61 and 62 in cut-out portion 57 lieclosely against segments 16 and 16a of boss 11. Wedged ends 63 and 64are weld sealed to the continuous side walls of an annular flangecountershaft box 25 which is seen in FIG- URES 1 and 2. The flangecountershaft box 25 has an annular passageway 26 therein aligned withpassageway 12 in boss 11. The upper inside portion of countershaftflange box 25 is beveled as at 27 so said beveled surface closelyfollows the inside annular surface of main frame shell 30.

Shell frame 30 may be rolled to form a one piece annular shell or it maybe formed from several curved Wall segments. The frame shell ispreferably positioned on the plate 50 so that an inner edge extends intocut-out seg ment 58 as at 35 (FIGURE 13). This permits a weld seal 1433to be placed between the bottom of the shell frame and the inside edgeof plate 50, as well as between the top of the plate and the side of theshell frame. The bottom of the frame shell has a plurality of slots 31(FIGURE 9) to closely engage upper arms such as 71 on the top surface ofplate 50. The slots have wedged ends 32 to provide a welding surfacewith said arms in which weld mass is placed as seen in the top sectionview of FIGURE 10. The main frame shell has a sealloped portion 33 whichis contoured to closely fit the upper continuous wall of flangecountershaft box 25. A portion of the edge of the scalloped portion iswedged as at 34 so that a weld seal with the continuous wall offiangecountershaft box 25 may be formed.

Intermediate the main frame shell 30 and center hub is a thickenedcurved wall partially encircling hub 10 and terminating against thejunction line of segments 14, 16 on one side and segments 14a,16a on theother side of boss 11. The wall 20 may be fixed to the top of plate 50by a weld seam 108. A wedged end is formed where the curved wallterminates so that a weld seam such as 102 may be placed between thewall and the boss.

An annular ring 40 is placed on top of the main shell frame 30. The topof the main shell frame has an asymmetrical wedged end, seen in FIGURE12, and is formed from a longer sloping face 41 and a shorter straightface 42. Weld seams 104 are formed between said wedged end and the upperring on the inside junction and outside junction of the shell frame 30and the upper ring 40. The upper ring is preferably fashioned fromarcuate segments which are secured by weld fillets 105 placed in thediverging space between wedged ends 43 and 44 of adjoining segments(FIGURE 11). The individual arcuate segments are preferably spaced andset by a flat bar 45 which is fixed between adjoining arcuate segments.Such a bar will usefully space, secure and position the chord segmentsfor subsequent application of the fillet weld seam 105. The upper ringwill receive the superstructure of the finally assembled gyratory conecrusher which includes the adjustment ring and the crushing bowl.

The fabricated plate 50 is supported by a plurality of lower arms orgussets 72 which join the bottom surface of plate 50' by sealing weld106 and the hub 10 by sealing weld 107. The lower arms should besufficient in number and sufiiciently spaced to provide proper supportfor the plate 50 and other structures on said plate. It is found thatfour or five such lower arms spaced about the hub will provide adequatesupport. At the corners of plate 50, corner upper arms (FIGURE 8) suchas 73 may be placed in slots 31 of shell frame 30. Similar upper arms 71(FIGURE 2) may be placed at the sides of the plate. Upper arms 71 and 73are secured in slots 31 by weld fillets. Such arms are sealed to the topsurface of plate 50 as at 109, and are weld sealed to the curved wall 20as at 110. A plurality of flange or shell frame ribs 78 (FIGURE 13) mayalso be interspersed between the upper arms and the corner upper arms toprovide added support between the shell frame 30 and the top surface ofthe plate 50. The flange ribs do not engage slots in the shell frame 30but are merely joined to the shell frame 30 by suitable weld means suchas 117, and are joined to the top surface of plate 50 by suitable weldmeans such as 118. The number of such flange ribs which are to be addedmay also be varied according to the rigidity and support desired betweenthe shell frame and the plate 50.

Feed platform ribs 75 are preferably coupled and disposed on oppositesides of a shell frame 30 by welds joining the ribs to shell frame 30 at112 and to the upper 'ring 40 at 113. The feed platform ribs aremodified with lug extensions 76 that may be used to support a feed boxin the superimposed structures of the finally assembled cone crusherassembly. A plurality of ribs 77 may be additionally spaced about theshell frame 30 and joined thereto by suitable welds 114, and joined tothe upper ring 40 by suitable welds 115. The number of such additionaltop ribs may be varied so long as they provide inthe aggregatesulficient support for the upper ring 40.

The top plan view shows the various structures of the shell frameassembly in appropriate positions and proper relationship. The upperring 40 is seen as composed of arcuate segments joined by fillet weldseams 105. The plate 50 is fixed to the shell frame 30 which thicknessis' shown by phantom outline. The center cast hub 10 and integral boss11 are properly positioned within the central bore 56. The bottom fiatportion 18 in boss 11 is formed from the inwardly turned side walls 17of the boss. The countershaft flange box 25 is shown secured betweenends 63 and 64 in phanotm outline. Intermediate the frame shell 30 andthe center cast hub 10 is the curved wall 20 which partially enclosesthe center hub and has one end terminating against straight segment 14and joined thereto by a fillet weld 102. The other end of the curvedwall is seen terminating against the straight segment 14a and sealedthereto by weld fillet 102. Upper arms 71 and 73 are joined to the topsurface of the plate 50 and to the cruved wall 20. 'The curved wall 20is partially supported by the inner annular band 60 of plate 50. Theupper arms are partially supported by an isthmus or connecting band 59which joins the inner annular band 60 with the outer portions of plate50. The upper arms '71 and 73 engage the slots 31 in shell frame 30, andtwo corner upper arms 73, 73 are shown extending from inner curved wall20 to one pair of bolt bosses 68. Flange ribs or shell frame ribs 78,78are shown as extending from the shell frame 30 to the other pair of boltbosses 68. Such ribs are joined to shell frame 30 and to the top surfaceof plate 50 by weld means. The bolt bosses 68 are apertured at 67. Suchbosses 68 are fixed to the corners of plate 50 by a weld 111 or thelike, and are superimposed over apertures 66 adapted to receive suitablebolts for fixing the plate 50 to an underlying foundation such as aconcrete block.

Feed platform ribs 75 join the upper ring to the shell frame 30, and areshown as coupled on opposite sides of the shell frame 30. Lugs 76 areextensions of the feed platform ribs 75, and are used to support anoverlying feed box. Top ribs 77 are shown in phantom outline as joiningthe upper ring 40 to shell frame 30.

The use and operation of my invention are as follows:

To cast a cone crusher frame in one piece is an expensive procedure, andsuch a cast cone crusher frame is bulky and heavy. A lighter, lesscumbersome and less expensive cone crusher frame may now be assembled byjoining fabricated parts to a center hub and countershaft boss, which isthe only component in the assembly that requires casting.

A one piece casting consisting of a center hub 10 and an integral boss11 is provided. The center hub has a passageway extending therethroughto receive an eccentric and a shaft. Keyway slots 9 are provided at theupper part of the hub to key eccentric bushing which will surround theeccentric. The boss 11 is a lateral extension from the hub and has apassageway 12 therein to receive the countershaft of a pinion. Thepinion will be located within the enclosure of the boss and will engagethe gear connected to the eccentric extending at the top of the hub. Theboss 11 has a straight front wall with generally even surface which isgenerally parallel with side 51 of the fabricated plate. The side wallsof the boss 11 are contoured to lie against sides 61 and 62 of thecut-out portion 57 in plate 50. The hub 10 lies in central bore 56 ofplate 50 and is sealed to the annular wedged end 55. Projecting wedge10a on the hub 10 contacts annular wedged end 55 at the respective highpoints of the wedges, and a fillet Weld seal 101 is placed in thediverging space formed between the two wedges. A curved wall 20 isspaced from hub 10 and encircles hub 10 up where the terminating endscontact boss 11. The curved wall 20 terminates in wedged ends 22, andthe high point of this wedged end is placed against the juncture linebetween segment 14 and segment 16 in the side wall of boss 11. Thiscontact forms diverging spaces which are filled with a fillet Weld seam102.

A flange countershaft box 25 is placed so the continuous side wallscontact wedged ends 63 and 64 in cut-out portion 57 of plate 50. Suchwedged ends are joined by weld seals to the continuous side walls of theannular countershaft box 25. The flange box 25has a passageway 26 whichis aligned generally with passageway 12 in boss 11, and the countershaftof a pinion will be inserted in said passageways 12 and 26. The flangebox 25 is beveled at its upper portion so that it closely adjoins theinternal annular surface of shell frame 31 A rolled annular shell frame30 is placed on the fabricated plate 50. The shell frame 30 has ascalloped lower portion contoured to engage the upper annular continuouswalls of countershaft flange box 25. A plurality of slots 31 are also inthe lower portion of shell frame 3! to engage upper arms 71 and cornerupper arms '73. The arms, in part, rest on connecting bands or isthmuses59 which are interspersed between cut-out segments 58 and which encirclecenter hub 10. The connecting bands 59 connect an inner annular band 66on which the curved wall 20 is supported and the outer portion of thefabricated plate 50. These cut-out segments result in a fabricated plateof lesser bulk and weight. Additional shell frame ribs 77 are placed tojoin the top surface of plate 50 to the shell frame 30.

A plurality of lower arms or gussets 72 are welded to the bottom surfaceof the plate 50 and to the hub to provide support for the plate.

An upper ring 4%) is placed on the top of the shell frame 31 and suchring may be constructed from several arcuate segments which are sealedalong their adjoining wedged ends by welds 11%. The upper ring 40 issupported by a plurality of top ribs 77 which join the upper ring to theshell frame 36 by suitable welds. Feed platform ribs 75 are also placedin generally the same position, that is, between the upper ring and theshell frame 30. These ribs 75 have lugs 76 connected thereto to supportan overlying feed box in the finally assembled cone crusher.

The cone crusher frame assembly may then be anchored on a suitablefoundation by inserting bolts through the common apertures 66 formed inthe bolt bosses 63 at the corners of the fabricated plate 56 The variousstructures of a gyratory cone crusher may then be placed in theassembled cone crushed frame.

The foregoing invention can now be practiced by those skilled in theart. Such skilled persons will know that the invention is notnecessarily restricted to the particular embodiments presented herein.The scope of the invention is to be defined by the terms of thefollowing claims as given meaning by the preceding description.

I claim:

1. A cone crusher frame assembly having a cast component and fabricatedcomponents which includes, in combination,

a hollow cast center hub adapted to house an eccentric for rotating ashaft, a countershaft boss having side walls integrally cast with thehub, a passageway in the boss to receive a countershaft,

a fabricated plate with a plurality of sides, a top and bottom, saidplates having a central bore partially encircling the hub, said plateattached to the hub at the central bore, a cut-out portion in the plateextending from the bore to one side of the plate, the cut-out portionengaging the side walls of the countershaft boss,

a countershaft flange box having a passageway aligned with thepassageway in the boss, said flange box attached to the plate at thecut-out portion,

a rolled annular main frame shell attached to the top of the plate, saidshell closely engaging the flange box,

a curved wall fixed to the plate intermediate the shell frame and thecenter hub, said curved wall surrounding the hub and attached to theside walls of the boss, and

an upper ring supported by and fixed to the main frame shell.

2. A cone crusher frame assembly as in claim I further characterized inthat the shell frame is slotted along its 3 lower edge and a pluralityof upper arms are seated in said slots and attached to the top of theplate.

3. A cone crusher frame assembly as in claim 1 further characterized inthat a plurality of supporting lower arms are attached to the bottom ofthe plate and to the hub.

4. A cone crusher frame assembly as in claim 1 further characterized inthat the shell frame is scalloped at its lower edge to closely fit theflange box.

5. A cone crusher frame assembly as in claim 1 further characterized inthat a plurality of ribs are attached to the upper ring and the mainshell frame, and some of said ribs are provided with projecting lugs toprovide a support for a superposed feed box.

6. A cone crusher frame assembly as in claim 1 further characterized inthat the upper inside portion of said countershaft flange box is beveledon the side towards the boss to closely follow the annular main frameshell.

7. A crusher frame assembly as in claim 6 further characterized by andincluding a plurality of ribs attached to the upper ring and the mainshell frame, and some of said ribs provided with projecting lugs toprovide a support for a superposed feed box.

8. A cone crusher frame assembly as in claim 1 further characterized inthat the plate has a plurality of cut-out segments spaced around thecentral bore.

9. A cone crusher frame assembly having a cast component and fabricatedcomponents which includes, in combination,

a hollow cast center hub adapted to house an eccentric for rotating ashaft, a countershaft boss having side walls integrally cast with thehub, a passageway in the boss adapted to receive a countershaft andpinion,

a fabricated plate having a top, a bottom, and four sides, a bore ofgenerally circular configuration, in the plate partially encircling thehub, said plate attached to the hub at the bore, said plate having acutout portion extending from the central bore to one side of the plate,the plate closely adjoining the side walls of the countershaft boss atthe cut-out portion,

an annular flange box proximate to one side of the plate and having apassageway aligned with the passageway in the boss, said flange boxattached in close engagement to the cut-out portion so an upper partextends above the top of the plate and lower part extends below thebottom of the plate,

cugout segments in the plate spaced around the center ore,

an annular main shell frame attached to the top of the plate, the shellframe having at its lower edge a scalloped portion to closely engage theupper annular flange box, and a plurality of slots engaging upper armson the top of the plate,

a curved wall attached to the plate intermediate the hub and shellframe, said curved wall extending to the side walls of the boss andsecured thereto,

a plurality of supporting lower arms attached to the hub and the bottomof the plate,

and an upper ring attached to the shell frame.

10. A cone crusher frame assembly having a cast component and fabricatedcomponents which include, in combination,

a hollow cast center hub adapted to house an eccentric for rotating ashaft, a countershaft boss having side walls integrally cast with thehub, a passageway in the boss adapted to receive a countershaft andpinion,

a fabricated plate having a top, a bottom, and four sides to form ageneral rectangle, a bore of generally circular configuration in thecenter of the plate, curved cut-out segments in the plate around thecentral bore, connecting bands interspersed between said segments toconnect an inner annular band of the plate with the outer portions ofthe plate, said bore partially encircling the middle of the hub, saidplate attached to the hub at the bore, said plate having a cut-outportion extending from the central bore to one side of the plate, theplate closely adjoining the side walls of the countershaft boss at thecut-out portion,

an annular flange box proximate to one side of the plate and having apassageway aligned with the passageway in the boss, said flange boxattached in closeengagement to the cut-out portion so that the upperhalf extends above the top of the plate and the lower half extends belowthe bottom of the plate,

an annular main shell frame supported on the outer portion of the plate,the shell frame having at its lower edge a curved scalloped portion toclosely engage the upper half of the flange box and a plurality of slotsengaging upper arms on top of the late,

a gurved wall intermediate the hub and shell frame, said curved wallsupported on the inner band, the ends of the curved wall extending tothe side walls of the bass and secured thereto,

a plurality of supporting lower arms attached to the hub and to thebottom of the plate, and

an upper ring attached to the top of the main shell frame.

11. A fabricated plate used in assembling a cone crusher frame whichincludes, in combination, a foursided plate of sufficient dimension torest on a foundation for a gyratory crusher, said plate having agenerally circular central bore adapted to closely fit the exteriorannular Wall of a cast hollow hub, a cut-out portion extending from thecentral bore to one side of the plate, the cut-out portion having sidesadapted to lie against the side walls of a countershaft boss integrallycast with the hub, and said cut-out portion further having sidesproximate to one side of the plate to lie against the wall of an annularflange box.

12. The structure of claim 11 further characterized in that the platehas a plurality of curved cut-out segments spaced around the centralbore.

13. The structure of claim 11 further characterized in that the platehas four sides in the general shape of a rectangle.

14. A fabricated plate used in assembling a cone crusher frame having acast hollow hub With annular side walls, a countershaft with angularside walls integral with the hub, a flange box with a continuous Wall,an annular shell frame, a curved wall and supporting arms which include,in combination,

a four-sided plate of suflicient dimension to rest on a foundation for agyratory crusher, a generally circular central bore in said plate,

a cut-out portion extending from the central bore to one side of theplate, the central bore dimensioned to closely fit the exterior annularwall of a cast hollow hub, the cut-out portion having straight sides tolie against the side walls of a countershaft boss integrally cast hub,said cut-out portion further having straight sides proximate to one sideof the plate to lie against the continuous wall of a flange box,

curved cut-out segments around the central bore, con- 19 meeting bandsinterspersed between said segments to connect an inner annular band withthe outer portions of the plate, said inner annular band adapted toreceive a curved intermediate wall extendhlg to the side walls of thecountershaft boss, said outer portion of the plate adapted to support anannular main shell frame, and said connecting bands adapted to supportupper arms engaging the top of the plate in the main shell frame.

15. A structure suitable for receiving components of 20 a completed conecrusher which includes, in combination,

a cast center hub having side walls around a passageway adapted toreceive an eccentric and shaft, a countershaft boss having side wallsintegrally cast with the hub, a passageway in the boss to receive acountershaft,

a flange box having continuous side walls and a passageway aligned withthe passageway in the boss,

90 a fabricated plate with a plurality of sides having a central borepartially encircling the side walls of the hub,

a cut-out portion in the plate extending from the bore to one side ofthe plate, the plate partly attached to the side walls of that boss atsaid cut-out portion and the plate partially attached to the side wallsof the flange box.

16. A structure suitable for receiving components of a completed conecrusher which includes, in combination,

a cast center hub having side walls around a passageway adapted toreceive an eccentric and shaft,

a fabricated plate with a top, a bottom and a plurality of sides, saidplate having a central bore partially encircling the side walls of thehub, and said plate attached to the hub at the central bore, wherebymultiple components may be attached to top and bottom of the plate, andthe hub.

References Cited in the file of this patent UNITED STATES PATENTS2,860,837 Werner Nov. 18, 1958

1. A CONE CRUSHER FRAME ASSEMBLY HAVING A CAST COMPONENT AND FABRICATEDCOMPONENTS WHICH INCLUDES, IN COMBINATION, A HOLLOW CAST CENTER HUBADAPTED TO HOUSE AN ECCENTRIC FOR ROTATING A SHAFT, A COUNTERSHAFT BOSSHAVING SIDE WALLS INTEGRALLY CAST WITH THE HUB, A PASSAGEWAY IN THE BOSSTO RECEIVE A COUNTERSHAFT, A FABRICATED PLATE WITH A PLURALITY OF SIDES,A TOP AND BOTTOM, SAID PLATES HAVING A CENTRAL BORE PARTIALLY ENCIRCLINGTHE HUB, SAID PLATE ATTACHED TO THE HUB AT THE CENTRAL BORE, A CUT-OUTPORTION IN THE PLATE EXTENDING FROM THE BORE TO ONE SIDE OF THE PLATE,THE CUT-OUT PORTION ENGAGING THE SIDE WALLS OF THE COUNTERSHAFT BOSS, ACOUNTERSHAFT FLANGE BOX HAVING A PASSAGEWAY ALIGNED WITH THE PASSAGEWAYIN THE BOSS, SAID FLANGE BOX ATTACHED TO THE PLATE AT THE CUT-OUTPORTION, A ROLLED ANNULAR MAIN FRAME SHELL ATTACHED TO THE TOP OF THEPLATE, SAID SHELL CLOSELY ENGAGING THE FLANGE BOX, A CURVED WALL FIXEDTO THE PLATE INTERMEDIATE THE SHELL FRAME AND THE CENTER HUB, SAIDCURVED WALL SURROUNDING THE HUB AND ATTACHED TO THE SIDE WALLS OF THEBOSS, AND AN UPPER RING SUPPORTED BY AND FIXED TO THE MAIN FRAME SHELL.